I did a crazy fun cosmetics Mystery Shop at the mall today. You can too! I currently conduct mystery shopping with an industry-leading company called BestMark, and enjoy the assignments they provide... and the free services and extra cash is definitely a plus! It's free to sign up as a BestMark shopper and you are able to view the opportunities in your area as soon as you are hired into the system. The best part is that I get to provide feedback about the experiences I have at local businesses and I get paid for it!
Here is a link to their free application:
BestMark has been in business for over 26 years and has all types of assignments (auditing, mystery shopping, exit interviews) across many industries, ranging from retail to automotive to restaurants and more!